Topic: YEEAAAAHHH !!! Got it! I'm a proud SOHC owner !

[ascanio1]

Hello to every one!

I am a new and proud CB750 SOHC owner!

In August I posted a lot of questions asking for help to buy the right CB750 and I have to say that I was positively surprised both by the quantity and quality of the replies I received: AMAZING! Thanks to this help I avoided many mistakes and waste of time and money.

I found a November 1972 bike which runs well except for the clutch which seems to slip a bit when I rev it up in 3rd or 4th gear, but over all the bodywork is not bad, considering that she's a 43 years old lady. My next endeavor is to enjoy restoring and caring for it with 2 main objectives:
A) Restoring original bodywork, possibly to look as new as possible;
B) Restoring perfect mechanical conditions;

For body-parts I wish to remain smack-on year-correct but for mechanics I don't mind using later improvements, just as anyone would have done in those years.

I love the 70's non-up-to-date character of this bike's mechanics. However, I want to be sure that I am not mistaking for "character" what may be a mechanical faults which I should repair!

1) The front brake is really lousy! Locking it is impossible and it is so inefficient that - at best - certainly not in an emergency: I can use it only to slow down! The rear drum brake, on the contrary, is so efficient that I am sure that it would lock in an emergency braking. I am aware of the drum's limitations but is it normal that the front brake is so lousy? Can the front disk be improved without installing modern brakes?
2) The engine takes more than 5 minutes to warm up (outside temp 5°C) before running smoothly. Is it normal? Once warm it idles really very, very regularly at 1,000rpm.
3) The engine revs very smoothly and regularly up to about 3,000rpm but then it becomes very reluctant to rev higher. It will run all the way to the red line (and beyond) but it's harsh and unwilling. Should I worry?
4) It smells really badly of burnt oil (but there is very little white smoke) while warming-up. Is it normal?
5) There is a beep-beep buzzer when the turn signals are on. Was this standard?

Can you help me to find correct period:
A) Ignition key copies (I only have one).
B) Owner's manual (English or Italian).
C) Original tools.
D) Seat cover. This seat has been modified and lowered by the previous Japanese owner. I found a replacement seat but it's very worn out.

Brief OT:
------------
In August Jerry had a brilliant idea: I should look for and buy the same model/colour which my dad had owned and ridden to Africa from Naples (Italy). I was unable to find the serial number of my dad's bike but my mum's family memories helped: the CB750 was bought new, after returning to live in Naples from Belgium (very early in 1971). On May 30th, 1974 my uncle got married and the bike appears in the far background of a picture of that day. Another clue was the memory of a heated argument that my parents had over the CB750: my dad showed up at a clinic on his new Laverda 1000, to congratulate the birth of another family member (my cousin Raphael, 21 December 1974). The argument was that dad's "old" Honda was less than 2 years old. That makes it an early 1973 bike, most likely a K2, as the new 1973 Honda models would not have hit the dealers until April that year. Mum's colour description was: "a horrible and repulsive shiny orange" which most likely was Flake Orange.
------------

Thanks in advance for who will invest his time/expertise to help me perfect my orange lady!

Tommaso

[ascanio1]

More pics to help me spot what's not year correct on my bike

[faux fiddy]

Nicely done.

If you have a key number Oklahoma Honda Suzuki has a number of pre-cut factory keys, I have bought a couple there.

Del City Oklahoma Honda Suzuki

www.okhonda-suzuki.com/

Del City Oklahoma Honda Suzuki Dealership, New & Used Bennche, Bunkhouse, Bushtec, Champion Trikes, Hannigan Trikes, Honda, Suzuki Powersports For ...

3400 South Sunnylane Road, Del City, OK 73115
(405) 672-1423

[Stev-o]

Congrats. 

1. Front brake should not lock up!  Upgrading lines to stainless braided could help.
2. Normal for the bike to take a few min to warm up.
3. Suggest the 3000 mile tune up
4. Burnt oil smell is not good. How many miles?
5. Yes. 

[78whiteorbs]

Congrats, she looks great! If you have only ever ridden modern bikes the front brakes will be something to get use to even at best. Replacing with braided steel lines and cleaning out the caliper and flushing the brakes should help along with resurfacing your rotor and pads if glazed.  Like driving an old truck remember to give yourself a little more stopping distance . After a good revitalizing they should be sufficient but again never compare to a modern bike. You are dealing with 40 year old tech here so keep that in mind. I know alotta guys that really like the way old bikes appeal to them visually but can never get over how they dont "feel" like a modern bike. My advise is love them for what they are and keep a new bike for those days you want top performance. Enjoy!

[grcamna2]

That sure is a Nice K2 ascanio1 

[Oldtech]

If you're open to modern upgrades then fit a new Nissin front master cylinder. You'll need one with a 16mm ( 5/8 inch) bore. Got one on my cb550 and my CBX. It will really wake up the brakes.

[Guido56]

Ciao Tommaso 
The manuals in Italian and English will find them here. '
http://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&sqi=2&ved=0CEMQFjAE&url=http%3A%2F%2Fwww.honda4fun.com%2F&ei=JsRVUtbtNoPmswbnrYDwAg&usg=AFQjCNHcBanqIfvvixY5FD7OUTYp-UQYYw&bvm=bv.53760139,d.Yms
When you come back in Italy come to rally Cereglio.
This and 'my 750


Te lo scrivo in italiano 
Le chiavi forse le trovi da Hondakeys.com.
I manuali sul sito che ti ho indicato oppure su questo.
Gli attrezzi si trovano su Ebay.DE a circa 100 €
La sella e' del modello K0 ma e' stata modificata.Se riesci a ripristinarla vale diversi soldini.
Il freno anteriore frena poco ma ho fatto rifare le pastiglie con materiale tenero e devo dire che non e'male.
Chiaramente per una moto di 40 anni,

[ekpent]

Actually looks like an early K3 or 1973 frame (221XXXX) with an early style ducktail seat where the foam may be modified or just smooshed down. Engine maybe a K4 with a 232xxxx starting serial number ?   Congrats on your find looks to be very clean and nice.   http://www.sohc4.net/cb750k-serial-numbers/

[goldarrow]

Did you end up buying local bike, or import to japan?

[Peterengland]

+1 about the front brake, lock it up = danger. don't do it, no need !

[Bankerdanny]

Beautiful bike, congratulations. The 5 minute warm up time is idling or riding? Every bike is different and 5 minutes is not excessive, but it will warm up faster when riding. I would expect that you should be able to completely open the choke within a kilometer when riding in moderate to warm temps.

[70CB750]

What Danny says, I hold the choke to the first Stop sign, about 800 meters.

And congrats on your new bike!

[Don R]

 I don't think he wants to lock the front brake, he illustrating the fact that it doesn't stop well. Servicing it as posted above will help, it should stop reasonably. I double disc'd one and loved it, there are better rotors available and better pads too.
 My K0 bike is like that, when it comes out of storage that's the first thing I'm working on.

[Sgt.Pinback]

Actually looks like an early K3 or 1973 frame (221XXXX) with an early style ducktail seat where the foam may be modified or just smooshed down. ..

As far as I know there are two types of KO ducktail seats: standard and low.

@Tommaso,
great looking survivor, congrats!

[Guido56]

Actually looks like an early K3 or 1973 frame (221XXXX) with an early style ducktail seat where the foam may be modified or just smooshed down. ..

As far as I know there are two types of KO ducktail seats: standard and low.

@Tommaso,
great looking survivor, congrats!

I did not know that there were two types of seat.

[dhall57]

Originally from the factory their wasn't as far as I know. The seat on Ascanio's bikes looks like it might be a repilca seat from Yamiya

http://www.yamiya750.com/index.php?main_page=index&cPath=123&sort=20a&language=en

Man that's a good looking K3. You aren't going to do the flipper-rue on it are you

[Sgt.Pinback]

Maybe Yamiya.

Found pic in a 1970 test with a low (?)  seat

[ekpent]

The pictured seat does look like a different contour though I have never heard of differences, at least on US models.  Seems I always learn new things here all the time though, especially with the real early models.
   Maybe he will get back and let us know if it is an old or new seat and if it has old dusty red foam in it.

[ascanio1]

If you have a key number Oklahoma Honda Suzuki has a number of pre-cut factory keys, I have bought a couple there.

The keys don't have any number but the ignition "lock" might. I'll check today, later.

[ascanio1]

@ 78whiteorbs, Peterengland & Stev-o,

Congrats.
1. Front brake should not lock up!  Upgrading lines to stainless braided could help.
2. Normal for the bike to take a few min to warm up.
3. Suggest the 3000 mile tune up
4. Burnt oil smell is not good. How many miles?
5. Yes.

1.
Of course locking the front disk is dangerous and undesirable if it happens at speed - the very purpose of disk brakes is to avoid that! But if I try to stop my Ducati or Benelli @ 20mph, using only the front brake, the bikes will come to a complete stop immediately. They may even lift the rear wheel. My darling old lady won't stop for many, many... meters, until I apply the rear drum!
3.
Please, would you link me to a page to check what that consists in? My mechanic has already tuned the carbs with a 4 cyl vacum instrument.
4.
Not many miles are shown: 34,000. But Ekpent pointed out that the engine/frame don't match. So it's likely that the owner fiddled with the miles, too.

What do you advise?

[ascanio1]

If you're open to modern upgrades then fit a new Nissin front master cylinder. You'll need one with a 16mm ( 5/8 inch) bore. Got one on my cb550 and my CBX. It will really wake up the brakes.

Do you have any pics? I want to see how much off they look on the bike...

[krusty]

For manuals I've used www.honda4fun.com
It's an Italian website.

[ascanio1]

Thanks Guido! Nice to meet a fellow Italian. I won't reply in Italian for the benefit of other members, but I appreciate you did.

Ciao Tommaso  The manuals in Italian and English will find them here. '
http://www.google.it/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&sqi=2&ved=0CEMQFjAE&url=http%3A%2F%2Fwww.honda4fun.com%2F&ei=JsRVUtbtNoPmswbnrYDwAg&usg=AFQjCNHcBanqIfvvixY5FD7OUTYp-UQYYw&bvm=bv.53760139,d.Yms

the website is offline but I meant an original book. Something to keep under the seat with the tools...

When you come back in Italy come to rally Cereglio.

I will certainly come, if you will ship my CB750 from Tokyo and back! I live in Tokyo! But... alternatively, if you have an extra CB750 I could borrow that one! 

Le chiavi forse le trovi da Hondakeys.com. I manuali sul sito che ti ho indicato oppure su questo. Gli attrezzi si trovano su Ebay.DE a circa 100 €
La sella e' del modello K0 ma e' stata modificata.Se riesci a ripristinarla vale diversi soldini. Il freno anteriore frena poco ma ho fatto rifare le pastiglie con materiale tenero e devo dire che non e'male.
Chiaramente per una moto di 40 anni,

I checked Hondakeys and today I will check if the master cylinder has a number on it.
As for manuals, I meant a paper copy to keep under the seat.

[ascanio1]

Actually looks like an early K3 or 1973 frame (221XXXX) with an early style ducktail seat where the foam may be modified or just smooshed down. Engine maybe a K4 with a 232xxxx starting serial number ?   Congrats on your find looks to be very clean and nice.   http://www.sohc4.net/cb750k-serial-numbers/

Thanks! I appreciate pointing out the mismatch and the correct model... I was not smart to not check the engine/frame match: I trusted the seller as he is had a 100% positive review on Japan's Yahoo Auctions with 176 bikes sold and specializes only in 1970's bikes. Evidently I was wrong to trust him as it seems that this is a K3 (not K2) with a K4 engine...

Well, all in all it's not too bad as I paid the equivalent of 5,600USD, including transport from Kyushu to Tokyo. I think that this bike was imported from the US to Japan as the instruments are in miles, not Km. I did not go through with my initial plan to buy the bike in the US and then ship it over to Japan (I live in Tokyo) but... fate did it for me!
 

I'll certainly try to get some discount for the misrepresentation, though it might be difficult as the seller is in the Kyushu Islands... many hundred miles away... but I won't report the listing as "fraud" even though it was listed as K2 and I was adamant on buying a K2 because of sentimental reasons.

I would like the forum's opinion:
1) Are the K2 and the K3 very different technically?
2) Is there a big difference in value between the 2 models, in the US?
3) If I keep the K3 body original, does the later K4 engine hurt the collector's value a lot?

I think that it should not make too much difference: from K3 to K6 there were not many changes and it does not modify the historical value. I think that it would have been different if it had been a K2 (or, worse a K1, K0) with a K4 engine...

I now realize why it was cheap... but I have to be honest, I am not affected in the least as far as ownership pleasure is concerned. I really don't care if it's a K2, 3, 4, 5 or 6 as they all look very similar to me. I would have been pi..ed off if I had bought a K3 listed as K1 (or K0)! The only real reason why I was glad to have bought a K2 instead of a K3 (4, 5 or 6) was not the value but the sentimental whim to retrace the footsteps of my dad who recently passed away: he rode a K2 with my mum (pillion) on the desert roads of Libya and Tunisia when I was a kid and I remember how fascinated I was when they returned home and told me about the bedouins, tea in the desert, sleeping under the stars on the sand, the dust in the face, etc etc... any kid would have fostered those memories into a myth... but it makes no difference to me if I am riding a K2 or a K3. I am still doing it in memory of my dad... and my wife and I have already started enjoying the rides and planning our own little "myths"!